Apparatus for completing a well



A. VAUGHN ETAL APPARATUS FOR COMPLETING A WELL Jan. 31, 1967 Original Filed June 27.

8 Sheets-Sheet l w E 0 v u 1 SW N R R A M7 V W h e m 0 \\A/ \fi N r! u 0 m A W. C J w a M Q r A k 0 g. b Y f r B r a A C Jan. 31, 1967 VAUGHN ETAL 3,301,337

APPARATUS FOR COMPLETING A WELL 8 Sheets-Sheet 2 Original Filed June 27. 1960 A M; j

Ar //7 or 1 0 09? Car/ 10:00 Je/f Jan. 31, 1967 A. VAUGHN ETAL 3,301,337

APPARATUS FOR COMPLETING A WELL Ar/fiur Vouy/rn Cor/ 10:00 Je/f V INVENTORJ BY AWT I ATTORIVLVJ Jan. 31, 1967 v A. VAUGHN ETAL 3,301,337-

APPARATUS FOR COMPLETING A WELL Original Filed June 27. 1960 8 Sheets-Sheet 5 E 37 Ar f/zur l/ouyfl/Y 42 39 Car/ laJra Je/f INVENTORJ 61 23!; g fiwi ATTORNEVJ Jan. 31, 1967 A. VAUGHN ETAL 3,301,337

APPARATUS FOR COMPLETING WELL Original Filed June 27. 1960 a Sheets-Sheet e Ar f/iz/r l/ouyfifi Car/ laJra Je/f INVENTORJ ATTO/P/VE w -3 1967 A. VAUGHN ETAL 3 APPARATUS FOR COMPLETING A WELL Original Filed June27. 1960 a Sheets$heet & a

, c 1 J /f f' 23 0/4' OJCO INVZVTORJ Jan. 31, 1967 A. VAUGHN ETAL 3,301,337

APPARATUS FOR COMPLETING A WELL Original Filed June 27. 1960 a Sheets-Sheet 8 .Car/ loJca Je/f Y INVENTORJ BY gzM 3,301,337 Patented Jan. 31, 1967 United States Patent Ofiice 3,301,337 I APPARATUS FOR COMPLETHNG A WELL Arthur Vaughn, Monroe, La, and Carl Lasco Self, Bir

mingham, Ala., assignors to Alpha Trace, Inc., Longview, Tex. Continuation of abandoned application Ser. No. 38,783, June 27, 1960. This application May 5, 1964, Ser. No.

15 Claims. (Cl. 17522) This application is a continuation of copending application Serial Number 38,783 filed June 27, 1960, now abandoned, and which application is in turn a continuation-in-p'art of copending applications, Serial Number 741,021, filed June 10, 1958, and Serial Number 854,859, filed November 23, 1959, both now abandoned.

This invention relates to an apparatus for completing a well by pushing a conduit laterally of the borehole into a formation to be produced or treated. In one of its aspects, it relates to an improved method for treating a formation, particularly for fracturing the same. In another of its aspects, it relates to an improved apparatus for placing a conduit late-rally of a borehole to thereby permit improved treating or production of a formation.

While reference is made herein to completion of a well, it will be understood that this term is used in its broadest sense to include not only the preparation of the well for flowing of oil from the formation including treating such formation in various fashions such as fracturing, acidizing, and other known processes, but also to include preparing a well as a water flooding well or one to be employed in other secondary recovery operations. The term is also applicable both to newly drilled wells and to wells which have previously been completed. Thus, the invention relates broadly, insofar as its end use is concerned, to preparing wells for production or for use in secondary recovery operations wherein it is desired to establish a lateral flowway between a formation and a borehole to permit ready flow of fluids to or from the formation.

It is known that many formations exist which contain large reserves of oil which cannot be recovered at a desirably high rate due to relatively low permeability of the formations or for other reasons. Attempts have been made to increase the production rate by fracturing the formation by application of fluid pressure thereto to develop cracks or fractures, and while such featuring has in many cases increased production, there are instances wherein it has not and in any event, a further increase in production over that afforded by fracturing is desired. One of the difficulties encountered with present fracturing methods arises-from the fact that the cement surrounding the casing is exposed to the fracturing fluid. Thus, after a casing has been landed, cement is flowed between the borehole wall and the casing and then after the cement has set,the casing is punctured by a mechanical means, a bullet or a shaped charge. Then upon application of the fracturing fluid through the punctured casing, its pressure is applied to the cement, tending to rupture the bond between the cement and the borehole wall or between the cement and casing. The fracturing fluid will take the path of least resistance and flow upwardly or downwardly along the cement interface rather than out into the formation. Other well treatments, such as aci-dizing, wherein a fluid is applied to a formation have encountered similar difficulties.

Another difiiculty encountered with completing a well by shooting the casing with a bullet or shaped charge arises from the fact that in some instances, the borehole will be considerably enlarged at a producing formation due to the sloughing off of the formation during drilling, cave-ins or the like. Then when the casing is cemented in place, there exists a considerable lateral thickness of cement between the casing and formation and in some cases, presently existing bullet or shaped charge guns cannot shoot through the entire thickness of ce' ment. Accordingly, the well cannot be completed from this formation.

.As indicated above, many formations have large reserves but the production rate is lower than desired because of relatively low permeability. Attempts have been made to increase the productivity of such wells by laying a pipe laterally of the borehole out into the formation to increase the sand face area from which the well can be produced. In some cases, a whip stock is set in the casing and then after a mill has cut a window in the casing, a bit is run in on a flexible drill string and a hole is drilled out by rotating the bit into the formation. Such an operation is relatively expensive since it requires a drilling rig to be set up, a whip stock to be set i and a Window to be milled in the casing, relatively large casing must be provided to allow room for the flexible drill string to be whipstocked out into the formation at an angle which even approaches the horizontal.

It has also been suggested that a lateral pipeline be laid by using pipe segments which are successively joined together and moved out into the formation. However, the apparatus suggested for carrying out this operation has been either so bulky as to require a borehole many feet in diameter (as caisson) or it has involved rotating the segments as they are pushed out into the formation so as to actually drill a hole into the formation which not only undully complicates the apparatus, but also does not permit it to be designed for use in ordinary sized casing, much less the slim hole casing which has become so popular today. Moreover, none of such apparatus for laying a segmented pipeline has been suited to puncturing an ordinary well casing and, moreover, it is apparent that such apparatus was suggested for use only in very soft formations.

It is therefore a general object of this invention to provide an apparatus for completing a well by pushing, without rotation, successive pipe segments out into a formation to form a pipe of fiowway thereinto from the borehole and which is adaptable to be used in a well cased with ordinary sized casing and even slirn hole casing, and which does not require pre-preparation of the well, such as by setting a whipstock, milling or the like before the conduit is laid into the formation.

Another object of the invention is to provide an apparatus for laying a segmented pipe laterally of a borehole in which the transverse force for focing a segment out into the formation is developed by a longitudinal movement along the borehole which, being of relatively unlimited length, permits sulficient vertical movement to develop a desired lateral force even though the diameter of the borehole may be relatively small.

Another object of the invention is to provide such an apparatus in which a longitudinally developed force is translated into a transverse force for pushing the segments out into the formation by a mechanical advantage linkage, such as a wedge, to thereby further increase the transverse force without necessitating a larged borehole for doing so.

Another object of the invention is to provide such an apparatus in which .a wedge is provided for translating longitudinal movement into transverse movement while at the same time increasing the mechanical advantage and wherein the wedge is provided with a means for distributing reaction force over a relatively large area and for increasing the ease in which the wedge may be re tracted during the initial portion of its return stroke.

Another object of the invention is to provide an appara-- tus for pushing segments without rotation out into a for-- mation wherein the segments are fed one-by-one into a. supporting means which positions them for pushing out. into the formation in line with preceding segments which have already been pushed out and in which those segments which have been pushed out are prevented from moving back so as to interfere with the feeding of a successive segment into position.

Another object of the invention is to provide an apparatus of the above general type adapted to be used on an electric cable.

Another object is to provide such an apparatus wherein a means is provided to hold the apparatus in fixed position while the segments are being forced out into the formation whereby successive segments are properly aligned with preceding segments, while at the same time, such holding means automatically positions the apparatus so that a substantial part of it is in abutment along its length with the casing to provide adequate distribution of the segment pushing reaction force along the casing.

Another object is to provide such an apparatus in which the first segment is especially adapted for punching a hole in the casing.

Another object is to provide such an apparatus wherein means are provided for sealing "between the segments and casing in a manner such that the seal is installed by the apparatus itself.

Other objects, advantages and features of the invention will be apparent from the specification, the claims and the drawings wherein:

FIGS. 1, 2 and 3 are schematic illustrations of the operation of one embodiment of this invention showing the manner in which pipe segments are driven out through a well easing into a surrounding formation;

FIG. 4 is an illustration of a well completed in accord ance with this invention and particularly illustrates how a flowway can be provided through an abnormally thick cement layer which is not capable of being shot by present day bullet or shaped charge methods;

FIG. 5 is a plan view of a well schematically illustrating how a formation can be treated, such as by fracturing, to obtain a full pattern of treatment;

FIG. 6 is a view, partially in section and partially in elevation, illustrating a plurality of segments as they are joined together while being pushed out into the formation and especially illustrating the design of the first segment;

FIGS. 7A and 7B together constitute a detailed vertical sectional view of the embodiment of the invention shown in FIGS. 1 to 3;

FIGS. 8A and 8B together constitute a view similar to FIGS. 7A and 7B except that the view is taken on the line 8-$ so that the view is ninety degrees from the view of FIGS. 7A and 7B;

FIGS. 9 through 13 are crosssectional views taken on the lines 99 through 1313 in FIGS. 7A and 713.

FIG. 14 is a vie-w taken on lines 1414 of FIG. 8A;

FIG. 15 is an enlargement of a portion of the tool showing in greater detail the pipe segment positioning means and the means for limiting retraction of a segment once it is pushed laterally of the tool;

FIG. 16 is an exploded view of the wedge and anvil construction shown in FIG. 73;

FIG. 17 is an illustration of how the punch segment punches a hole through the casing and also illustrates means for sealing between the segmented pipe string and the casing;

FIGS. 18 and 19 illustrate another means for forming such a seal;

FIGS. 20 and 21 illustrate a booster means for initiating a perforation in a casing;

FIG. 22 illustrates an alternative means for setting slips which hold the apparatus in a fixed position in the casing;

FIG. 23 illustrates an arrangement for preventing the casing from egg-shaping while it is being perforated; and

4 FIGS. 24A and 24B illustrate one embodiment of the apparatus of this invention adapted for operation by an electric cable.

Like characters of reference are used throughout the several views to designate like parts.

Referring to FIGS. 1 to 3, the apparatus of this invention (hereinafter usually referred to as tool) generally comprises a housing 10 adapted to be lowered into a well bore, such as through a casing 11, until it is opposite .a formation A into which a pipe is to be laid. The hous- :ing carries suitable holding means 12 adapted to grip the casing and hold the tool in fixed position during the pipe laying operation. Carried by the housing is a means 13 for supplying a plurality of pipe segments 14 to a holding means 15 which is adapted to receive a segment and position it so that it can be pushed without rotation out into the formation. Power means are provided for supplying the segment pushing force and it includes an element movable longitudinally of the casing to develop a force which is translated into a transverse force for pushing the segments laterally of the tool. In the embodiment of FIGS. 1 to 3, the power means includes a power cylinder and piston assembly 16, the piston being connected to a mechanical advantage linkage 17, here shown in the form of a wedge, which translates the longitudinal force developed :by the piston-cylinder assembly into a lateral force and applies such force to a force transmitting connection 18. The latter is reciprocated transversely of the tool to first push a pipe segment out into the formation and then is retracted to permit a new segment to be fed into the supporting means. Power for reciprocating the piston of assembly 16 is supplied by reciprocating a long-stroke piston in a power generating means 19, the latter being connected hydraulically via a conduit 20 to the assembly 16. The reciprocation of the piston of the power generating means 19 can be accomplished in numerous ways, including using a sucker rod, tubing or other string 21 augmented by weights 22 if desired. Alternatively, the power can be supplied by suitable sandline or 'wireline, in which case weights 22 should be used.

Thus, the overall operation of the tool involves first lowering the tool into the well, and then setting the holding means 12 so as to hold the tool in a fixed position. The string 21 is then lowered to actuate the power generating mean-s 19 which in turn actuates assembly 16 to causing the linkage 17 to move upwardly. This in turn moves the force transmitting means to the left in FIGS. 1 to 3. During its initial movement to the left of FIG. 1, the force transmitting means drives the first segment 14a laterally of the housing and at least partially through casing 10. Upon raising of string 21, the force transmitting connection 18 is retracted and a second segment 14 is fed into supporting means 15 from the supply means 13. Then upon transmitting means 18 again moving to the left, a second segment is forced out behind and joined to the first segment, driving the latter further out into the formation. A repeated number of these operations can be made, resulting in a single string of connected segments being placed in the formation.

Referring now to FIGS. 7A through 8B and the related cross-sections, as well as to FIGS. 15 and 16, the pipe segment holding means includes a solid section 23 fixed in housing 111 and having an upper cut out portion or saddle 24 adapted to receive a pipe segment and position it for pushing out through an opening 25 in housing 16 and thence into the formation. In order to strengthen the housing and to provide a guide for the wedge hereinafter described, solid sections 23a and 23b can be provided as shown in FIG. 11, or sections 23 through 2317 can all be combined into one piece.

The segment supplying means 13 is herein illustrated as including a chute or magazine 26 which is preferably of rectangular cross-section so as tobe adapted to hold a plurality of the pipe segments in stacked relation. It will be noted that the magazine has internal flanges 26a so S that the noses 27 of the segments ride between these flanges. The flanges extend downwardly, as does the entire magazine, to lie closely adjacent the saddle 24. In the preferred construction, a magazine extends well down into the saddle and the flanges 26a are cut away so that, together with the lower part of the saddle, they define a circular opening only slightly larger than the diameter of the segments. The rear of the magazine is likewise cut away to provide a hole just large enough to receive the nose 28 of the anvil 29.

With this construction, it can be seen that as anvil 29 is moved to the left in FIG. 7B, a segment will be pushed out through opening 25. During this operation, the next segement in the magazine 26 will ride on top of the segment being pushed out as well as on top of the nose 28, which is slightly flattened on top to facilitate its sliding under the lowest segment in the magazine. During retraction of the anvil, the next segment will continue to ride upon nose 28 until the same has been fully retracted, after which the segment will drop down into saddle 24. As the anvil nose is being withdrawn, the next segement above cannot tip because its front end will be engaging the flanges 26a and because the depth of the magazine from front to back is only slightly greater than the length of the segment whereby the segment cannot move or tilt downwardly until the anvil nose has been fully retracted.

Means are provided for mounting the anvil in the housing to permit transverse reciprocation of the anvil while limiting its movement longitudinally of the housing. Such means can be afforded by providing slots 30 in the housing which act as guides for slides 31. Preferably, the slides 31 have a flat upper surface affording an increased bearing area against the upper sides of the slot to better distribute the upper component of force generated by the action of the wedge on the anvil. Also, wipers 32 are preferably provided on the slides to prevent accumulation of foreign substances, such as grit, in the slots.

In a preferred construction, a wedge 33 is mounted in the housing for reciprocation longitudinally thereof. As here shown, the wedge 33 is guided by solid sections 23a and 23b and it has a sliding contact with the backside of housing which preferably is provided with a filler member 34 to'provide a flat bearing surface against which the wedge can act.

The anvil is connected to the wedge in such a manner that the anvil can be transversely reciprocated responsive to longitudinal reciprocation of the wedge. This connection can comprise slides 35 on the anvil disposed in guideways 36 in the wedge.

The tool shown in the drawings was developed to exert force on the nose of the first or piercing segment of several hundred tons per square inch and in tools of this type, it is desirable to provide not only means for adequately distributing the reaction to this force, but also facilitating the initial retraction of the wedge. Thus, back pressure plate 37 can be disposed in a recess 3-8 in the wedge or, if desired, in the housing. Antifriction means, here shown as roller bearings 39, are provided between the pressure plate and the wedge. By making the length of recess 38 greater than the length of pressure plate 37,

it will be seen that as the wedge begins moving upwardly, the pressure plate will" remain stationary until its lower end abuts the lower end 40 of the recess. Thereafter, the pressure plate moves up with the wedge until the latter has reached its fully extended position. Then as the wedge begins the initial portion of its retractionstroke, pressure plate 37 remains stationary until its upper end abuts the upper end 41 of the recess. During this portion of the movement of the wedge, bearings 39 are active so as to make the force required to move the wedge relative to the pressure plate much less than that required to move the pressure plate relative to the housing. As a result, the initial portion of the return stroke of the wedge, which unlocks the wedge, can be made with relative ease.

In a similar manner, a pressure plate 42 can be provided in a recess 43 (which also contains bearings 44) 6 in the sloping face of the wedge for engagement with the anvil during a major part of its driving stroke. Here again, the retraction of the wedge will be eased during the initial portion of its retraction.

Where only relatively low penetrating forces must be developed, either or both of the pressure plates can be eliminated. When the front pressure plate is eliminated, roller bearings may be provided within a recess (not shown) in the face of the anvil which contacts the wedge to reduce the friction .therebetween.

Power mean-s is provided for generating a force by movement of an element in a direction longitudinal of the housing and then this movement is converted to a transverse movement by the action of a suitable mechanism such as the wedge and anvil. As illustrated in FIGS. 7A through 8A, the power means includes a power cylinder 45 having a power piston 46 disposed therein and connected to the anvil via a guide 47. The lower end of the power piston is connected by conduit 20 to the lower end of a power generating cylinder 4-8. A power generating piston 49 is adapted to be reciprocated in cylinder 48 and can comprise a single length of high polished, uniform diameter rod having a sliding seal 50 with cylinder 48. The rod is disposed in a tubular slotted guide 51. Its upper end is connected by an car 52 to a guide 53 which in turn is connected to an actuating rod 54. The guide 53 can be held in centered position by a plurality of longitudinal slides 55, made of a ma terial such as brass, and slidably engaging the interior of the housing.

By making piston 49 small, relative to piston 46, and by providing it with a long stroke, a large force can be generated. With piston 49 having a diameter of inch and a stroke of IOfeet, piston 46 with a diameter of 2% inches can be made to travel about 8 inches. Then by making wedge 33 with a 12 face, the anvil can be made to travel about 1 /2 inches. Thus, a 10-foot movement is converted into a 1 /2 inch movement with a corresponding multiplication of the force applied to piston 49.

To aid in retracting the wedge, a return spring 56 can be positioned between an abutment 57 fixed to the housing and another abutment 58 slidable'in the housing and engageable by the upper end of the wedge. A guide rod 58a is fixed to abutment 58 and extends upwardly through spring 56 as a guide and thence through an opening in abutment 57. Thus, as the wedge moves upwardly, spring 56 will be compressed to store energy to move the wedge downwardly as piston 49 is retracted. If desired, a helper string 59 can be attached to the lower end of segment 23 to be compressed by guide 47 upon upward movement of the wedge.

As indicated above, means is provided for engaging the casing to 'hold the apparatus in fixed position during the operation of pushing the segments out into the formation. Any suitable type of such means can be employed, but the one herein illustrated is believed to be of special advantage. It includes slips 60 and 61 having serrated pipe gripping faces 62. The wedges are contained in a carrier 63 which is movable longitudinally relative to housing 10 by virtue of a con-nection thereto by bolts 64 slidably extending through openings 65 in the carrier. Suitable springs may be provided to hold the slips in retracted position until they are to be expanded. The expanding means i here shown as a wedge 66 carried by the housing and adapted to extend between slips upon movement of the siip carrier 63 upwardly relative to the housing. It will be noted that wedge 66 has a straight side 67 abutting slip 60 while its other side is cut away as at 68. Then as the wedge moves down between the slips, slip 60 will remain relatively stationary while slip 61 will be moved laterally outwardly. By making slip 60 of proper width, its pipe gripping face 62 can be made to remain flush with the housing 10 when the wedge is in both its upper and lower positions. Then, since slip 61 is moved outwardly to engage the casing, it will be apparent that when the slips are expanded, housing 10 will be moved so that its backside is against the casing, thereby providing a substantial bearing area between the housing and casing so the reaction force generated by pushing the segments outwardly can be distributed over a substantial area.

In operation, a casing collar stop 67 or other suitable abutment can be run into the well and positioned at the point where the lower end of the tool is to be positioned. Alternately, other kinds of stops can be used such as a tail pipe attached to the lower end of the slip carrier to extend between the slip carrier and the bottom of the hole or in some cases, the slips can even be set on the bottom of the well. In any event, as the tool moves downwardly and contacts the abutment, the slip carrier is supported so that upon continued downward movement of the tool, the slip setting wedge 66 moves downwardly between the slips and causes them to grip the casing. The tool is then ready for pushing the segments out into the formation. As the supporting string 21 is slacked off, piston 49 will move downwardly through cylinder 48, forcing hydraulic fluid via conduit into the lower end of cylinder 45. This pushes piston 46 upwardly, thereby raising the wedge. As the wedge is raised, anvil 29 is moved to the left, pushing the first segment outwardly of the tool. The string 21 is then drawn upwardly, thereby permitting spring 56 to push the anvil and power piston 46 downwardly to retracted position. This retracts the anvil, permitting another pipe segment to fall into the saddle. The operation is then repeated, driving another segment out into the formation. Any desired number of segments can thus be driven out into the formation to provide a pipe extending many feet into the formation. After the desired number of segments have been driven out, string 21 can be picked up, which automatically unseats the slips and the tool can be withdrawn from the hole.

While a number of segment designs can be used, the one detailed in FIG. 6 is preferred. The first segment 14a is generally in the form of a truncated pyramid or core and has a flat nose 14b which acts a a punch in initially rupturing the casing. Extending back from the nose are a plurality of shearing ribs Me which act to enlarge the initially punched hole in the casing, peeling out the material around the hole much in the manner a banana is peeled. It has been found that particularly when heavy wall casing is to be perforated, the blunt nose 14b is important in that it provides an adequate area for distributing the force necessary to cause the casing to yield without deformation of the nose of the first pipe segment. The ribs 14c act to shear the casing so that it can be peeled back to form an opening of sufiicient size to pass the segment.

The succeeding segments 14 are each preferably formed with an annular nose 27 adapted to mate in a complementary recess 14d in the rear of a preceding segment. By making the diameter of the nose at point Me slightly larger than the internal diameter of the recess 14d at the same point, for example, 0.002 inch larger, the nose of one segment wi l become tightly wedged in the recess of a preceding segment and as a result, not only will a fluid tight joint be formed, but one which is sufficiently strong to resist parting of the segments under the conditions likely to be incurred in an oil well. Each of the segments Tut is provided with an internal passage 63 and the walls of the segments may be either perforate or imperforate. If they are to be perforate, an opening 69 can be provided in the wall with a screen 7% across this opening. Such screen can be made fine to prevent intrusion of formation particles into passage 68 in the segments.

Normally, when the first segment 14a is pushed out against the casing, it will only partially perforate the same as shown in FIG. 2. As a result, the casing will tend to move the first segment back toward saddle 24 so as to interfere with the feeding of a succeeding segment into the saddle upon retraction of the anvil. To prevent this, means are provided for gripping the segment to hold it and prevent it from backing into the saddle sufficiently far as to interfere with feeding another segment into the saddle. Such means can comprise a pair of fingers 71 and 72 placed on opposite sides of the opening through which the segments emerge. Each finger has a means for gripping the segment and this means is herein shown as including a shoulder 7 3 which the finger can move behind a segment to grip the rear end thereof. Each of the fingers are mounted for circumferential movement with respect to the housing in the directions of the arrows shown in FIG. 15 so that they can be readily spread apart to permit a segment to pass theret'nro-ugh. After the segment has passed between the fingers, they are moved toward each other by springs 74 so as to move shoulders 73 behind the segment which has just been pushed from the saddle. In this connection, it will be noted that the nose of the anvil is beveled, as at 75, which permits the fingers to move in behind the segment before the anvil releases the same.

While this means for preventing backward movement of the segments has been found particularly important in connection with holding the segments until the casing has been fully perforated, there may be formations sufiiciently hard and resilient to also require the use of these fingers even after the casing has been perforated. Moreover, if there is any tendency for housing 10 to move toward the opening in the casing upon retraction of the anvil, the fingers will grip the segment and prevent such movement from interfering with the feeding of a new segment into the saddle.

As will be more fully explained below, one advantage of this invention is that it provides a flowway through a formation while isolating the cement around the casing from contact with the fluid in the flowway. To accomplish this, means are preferably provided which form a seal between the casing and the last segment to be driven. Several forms of seals can be provided, but the ones shown in the drawing are now preferred. Thus, in FIG. 17, a ring 76 of resilient material, such as rubber, is positioned around the nose of the first segment. Ring 76 is preferably made to have a smaller inner diameter than the outer diameter of the segments and is pre-positioned on the first segment so that upon driving the segment out through the casing, the ring will be pushed back and expanded and will ride against the casing as succeeding segments are driven outwardly. Since the last segment to be driven can be left with a portion thereof protruding inside of the casing, the ring will form an effective seal between such portion and the casing.

A more preferred seal is shown in FIGS. 18 and 19. In this construction, the last segment includes a steel tube adapted to be extended into the recess 78 of the next-tolast segment. Surrounding tube 77 is a material 7 9, such as lead or plastic, which can be relatively easily permanently deformed. The rear end of the next-to-last segment is relieved as at 80 so that when the last segment is pushed, tube 77 will move into the next-to-last segment white the anvil pushes against the lead or other deformable material, causing it to be extruded over relief Sfi and then forced into tight engagement with the casing 10 as shown in FIG. 19.

In some instances, it may be desired to provide a booster for initiating puncturing of the tubing. Thus, as shown in FIG. 20, a conventional casing perforating bullet 81 can be situated in a recess in the nose of the first segment 14a. A suitable explosive 82 is provided behind the bullet to be detonated upon segment 14 pushing piston 83 forward against the explosive. This causes the bullet to perforate the casing, after which piston 83 can be pushed against shoulder 84 and segment 14a then pushed on out through the casing, shearing it out as described above. Alternatively, a shaped charge can be fastened to the nose of the first segment 14a to be fired by pressing a primer 86 such as by pushing the nose of segment 14a against the primer. Electrical firing can also be used. Thereafter, the first segment can. move out through the hole formed by the shaped charge, and enlarge the sarne to accommodate the segments.

Referring to FIGS. 24A and 24B, there is shown a tool of the above general type which is adapted to be used on an electric cable such as found in ordinary well logging units. In the particular design shown, the power generating piston and cylinder have been replaced by a pump and reservoir 87. The pump is of the reversible, positive displacement type and is powered by a reversible electric motor 88. The motor, of course, is connected to suitable conductors in electric cable to receive power therefrom. Then upon actuation of suitable controls at the surface, the motor can be caused to drive the pump so as to pump hydraulic fluid from the reservoir into the power cylinder-pisten assembly 16 to move wedge 33 upwardly as above described. When the wedge has completed its stroke, a limit switch 89 signals the operator of such and the operator can reverse the motor so that the return spring can move the wedge downwardly as the motor pumps hydraulic fluid from the power cylinder 16 back to the reservoir. Another limit switch 90 is provided to signal when the wedge has been fully retracted. If desired, the limit switches 89 and 90 can be connected in the motor circuit so as to automatically reverse th same at each end of the stroke.

Various types of pumps can be used as part of the pump-reservoir 87, including piston pumps, gear pumps, etc. Also, the pump and reservoir 87 and power cylinder-piston assembly 16 can be replaced with a suitable mechanical advantage mechanism such as a vertical rod threaded to wedge 33 and connected to motor 88 through a suitable speed reducing mechanism giving the requisite mechanical advantage.

In order to permit this tool to be handled by the usual two-man logging crew, it can be divided into sections as illustrated in FIG. 24B. Thus, the lower section a can include the power generating mechanism, etc. shown in FIG. 24A and one or more upper sections can be provided to hold sections of magazine 26 as well as to provide the housing for the electric cable connections to the various motors, indicators, and the like in the lower sections. Thus, the upper section can comprise a housing like having a portion 26a of the magazine therein adapted to mate, when the housing sections are assembled, with another magazine section 2619 in the lower housing section. A plug 91, fixed in the upper housing section, can have a close fit with the lower housing section when inserted thereinto and it is held in place by bolts 92. In this manner, the various housing sections can be assembled as one rigid unit. Of course, intermediate housing sections can be provided between sections 10a and 1011, with each containing a magazine section positioned to mate with the magazine sections above and below in order to provide more segments to drive a longer pipe out into the formation.

When the electric cable type of tool is used, it is preferred that slips be set independently of any abutment or stop in the Well. This can be accomplished by providing a motor 93 connected by suitable gearing 94 to a rod 95 which is threaded into wedge 66. Then, as the motor 93 is turned in one direction, the wedge will move downwardly to expand the slips 6t) and 61 into gripping engagement with the casing, the slips being carried on a carrier 63a which is fixed to the housing 10. Upon re-. versing the motor, the wedge can be withdrawn so that the slips can be retracted.

As indicated above, considerable force is required to drive the first segment through the casing. This operation tends to cause the casing to egg shape, that is, to become oval in cross-section with the major axis of the oval coincident with the axis of the segments being driven through the casing. To reduce or eliminate this tendency,

a pair of slips 96 can be mounted in the housing on opposite sides of anvil 29 to push'out the casing at the points where it tends to bow inwardly. These slips can be expanded by expanders 97 which Wedge the slips outwardly upon being driven upwardly by motors 98 via gears 99 and threaded rod 100. Motors 98 are of course connected to leads in the electric cable and can be controlled from the surface so as to expand and retract slips 96.

As indicated in FIG. 19, a portion of the last segment protrudes into the casing. To permit ready withdrawal of thetool, a groove 101 can be provided along the length of the housing and slip 61 from saddle 24 downward. This groove readily permits the tool to be drawn upwardly even though the last segment protrudes into the casing.

Referring to FIG. 4, there is illustrated a well from which a plurality of segmented pipes have been driven into a formation. It will be noted that during drilling of the well, the borehole became enlarged at 102 so that when the casing was cemented in, a thick layer of cement surrounded the casing in the region of this enlargement. In some wells, this increased thickness of cement has been suflicient to prevent perforating by conventional gun or shaped charge methods so that the well could not be completed. In accordance with the instant invention, the segmented pipes can be driven out through the concrete even though its thickness may be many feet.

Again referring to FIG. 4, it will be noted that the segments first driven into the formation have lateral openings 69 therein similar to that shown in FIG. 6. The final ones of the segments are imperforate in that openings 69 are omitted. The number of imperforate segments are sufficient that the resulting imperforate section of the pipe extends well beyond cement 103. As a result, fracturing fluid or other treating agents can be pumped from the casing out through the pipe into the formation while being isolated from the cement by the imperforate sections. When fracturing, the fracturing fluid cannot apply pressure to the cement to fracture it and the fluid cannot flow along the interface 194 between the cement and the formation or the interface 105 between the casing and the cement. sured that the fracturing fluid is being delivered to the formation and is not flowing up or down the hole along one of the faces MP4 or 105. Similarly, when acidizing, the operator can be assured that the acid is getting out into the formation and that its strength is not being dissipated acting on the cement. Moreover, the imperforate sections aid in preventing water intrusion. Thus, it is not uncommon for water to flow upwardly between the cement and easing, thence into the perforation of the casing. With the instant invention, the water cannot so flow.

Referring to FIG. 5, there is shown a layout for obtaining a substantial full fracturing pattern. Thus, a plurality of the pipes have been driven out into the formation with each being angularly spaced from the other about the circumference of the borehole. Each pipe has an inner imperforate section and an outer perforate section. The length of the imperforate sections varies from pipe to pipe so that a uniform fracturing pattern is obtained. Preferably, the imperforate sections of alternate ones of said pipes are longer than the imperforate sections of the pipes therebetween. For example, L2 is made longer than L1, L4 longer than L3, L6 longer than L5, etc. Also, the perforate sections of the pipes with the shorter imperforate sections are made longer than the perforate sections of the pipes therebetween. In effect, then, the pipes are arranged so that substantially th entire formation for a given distance from the borehole is subjected to fracturing fluid.

Water flooding and other necessary recovery operations can be improved by using this invention. In such operations, the invention permits the Water or other fluid to be placed out into the formation away from the borehole As a result of this, the operator can be as-- to assure that the drive is against the oil bearing formation instead of against the cement. It is possible to load the outer segments of each pipe with an explosive and after the pipe has been laid, to explode the segments to develop a cavern in the formation. Then another pipe can be driven out into this cavern and water flooding begun. After the cavern has filled with water, it will provide a large area for the face of the drive, thereby exposing more of the formation of the drive.

It is contemplated that saddle 24, anvil 29 and wedge 33 can be oriented so that segments can be driven out from the borehole at an angle other than 90 from the longitudinal axis of the borehole. It is also contemplated that two or more strings of segments can be simultaneously driven into the formation by providing additional saddles and anvils, the latter being actuated by either a plurality of separate wedges or by a single wedge having a plurality of inclined faces, one for each string to be driven. In cases where two or more strings are simultaneously driven, it is preferred that the saddles be oriented syrnetrically about the circumference of the tool so that the reaction force incurred in driving one string will be at least partially balanced by the reaction force incurred in driving another string. For example, if two strings are to be driven, the saddles should be on opposite sides of the tool so that the reaction forces tend to balance.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the composition and method.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

What is claimed is:

1. An apparatus for forcing a plurality of pipe segments from a borehole of a well laterally into a formation so as to form a fiowway between the formation and the borehole comprising an elongated housing adapted to be lowered into the borehole, means for supporting a pipe segment in position so that it can be pushed laterally of the housing into the formation, means in the housing for holding a supply of said segments and for feeding them one-by-one into said supporting means as a preceding segment is pushed therefrom, force transmitting means for pushing said segments without rotation from said supporting means out into the formation including a part mounted for reciprocation transversely of the housing in .the direction the segments are to be pushed and positioned :to engage the rear end of a segment in the supporting :means to apply a pushing force to such segment, force generating means in said housing including means movalble longitudinally of the housing to generate a longitudinal :force with respect to said housing, force multiplying means connecting said longitudinally movable means and said force transmitting means and converting and multiplying :said longitudial force into a greater transverse force :applied to said force transmitting means to move it in one transverse direction to push the segment laterally of the housing, said force multiplying means being a wedge longitudinally reciprocal in the housing and engaging the force transmitting means to move the latter laterally as the wedge is reciprocated and means for moving said force transmitting means in an opposite transverse direction after the segment has been pushed laterally of the housing.

2. The apparatus of claim 1 in combination with a plurality of pipe segments in said pipe segment supply means, the first of said segments having a nose flat in a radial plane of the first segment and of substantially lesser diameter than that of the remainder of the segments to facilitate puncturing of the casing.

3. The apparatus of claim 2 wherein shear ribs are provided diverging from the nose toward the rear of the first segment.

4. The apparatus of claim 1 wherein the last segment has an annulus of readily deformable material adapted to be deformed by the force transmitting means into a seal between the next-to-the-last segment and the casing.-

5. An apparatus for forcing a plurality of pipe segments from a borehole of a well laterally into a formation so as to form a fiowway between the formation and borehole comprising an elongated housing adapted to be lowered into the well, means in the housing for supplying said segments .one-by-one and for positioning the segments so supplied so they can be pushed laterally without rotation out into the formation, anvil means, means mounting the anvil means in the housing for reciprocal movement transversely of the housing toward and away from a pipe segment positioned to be pushed into the formation but limiting the anvil means movement longitudinally of the housing, wedge means mounted for reciprocal movement longitudinally of the housing and engaging the anvil means to urge the same toward a positioned pipe segment, power means for reciprocating the wedge means longitudinally of the housing and means for moving the anvil means away from a pipe segment after the latter has been pushed laterally of the housing.

6. The apparatus of claim 5 wherein the wedge means includes a pressure plate between the wedge of the wedge means and the side of the housing opposite that from which the segments are pushed, antifriction means between the pressure plate and one of the wedge and housing, said pressure plate being mounted for limited longitudinal movement with respect to said one of the wedge and housing whereby the wedge can be retracted with less force than that required to advance it.

7. The apparatus of claim 5 wherein the wedge of the wedge means has a backside opposite the inclined face thereof engaged by the anvil with a longitudinal recess in the backside, a pressure plate within said recess engaging the housing and of a length less than that of the recess, and antifriction means between the wedge and pressure plate whereby the wedge can be retracted through an initial portion of its return stroke by moving relative to said pressure plate thereby reducing the force required for such initial retraction.

8. The apparatus of claim 7 wherein the inclined face of the wedge has a frontal pressure plate extending therealong and mounted for limited movement longitudinally of said inclined face and positioned to abut the anvil during at least a final portion of the advance stroke of the wedge, and antifriction means between the wedge and anvil.

A An apparatus for forcing a plurality of pipe segments from a borehole of a well laterally into a formation so as to form a flowway between the formation and borehole comprising an elongated housing adapted to be lowered into the "borehole, means for supporting a pipe segment in position so that it can be pushed laterally of the housing into the formation, means within the housing for holding a supply of said segments and for feeding them one-by-one into said supporting means as the preceding segment is pushed therefrom, power means for pushing the thusly positioned segments laterally of the housing including a part reciprocal transversely of the housing and engagable with a segment after it has been fed into said supporting means to push such segment laterally of the housing, means for retracting said part after a segment has been moved laterally of the housing and means carried by the housing and engaging a segment after it has been pushed laterally of the housing to limit move ment of such segment back toward the housing sufliciently to prevent another segment being fed into said supporting means while said part is being retracted.

if. The apparatus of claim 9 wherein said segment engaging means includes a pair of fingers arranged on opposite sides of the segments as they are pushed from the housing, said fingers being movable apart to permit a segment to move outwardly therebetween and then movable toward each other to engage a segment to hold the same and prevent its moving sufficiently far back into the supporting means as to interfere with the feeding of a succeeding segment into the supporting means.

11. The apparatus of claim 10 wherein the fingers are movable circumferentially of the housing and means are provided resiliently biasing the fingers toward each other.

12. An apparatus for forcing a plurality of pipe segments from a borehole of a well laterally into a formation so as to form a llowway between the formation and the borehole comprising an elongated housing adapted to be lowered into the well, means for supporting a pipe segment in position so that it can be pushed without rotation laterally of the housing into the formation, means in the housing for holding a supply of said segments and for feeding them one-by-one into said supporting means as a preceding segment is pushed therefrom, power means for pushing said segments without rotation laterally of the housing, means carried by the housing and expandable to place portions thereof in gripping engagement with the casing to fixedly position the housing in the casing while the segments are being pushed into the formation, said expandable means when expanded positioning the backside of the housing opposite that from which the segments are pushed against the casing whereby the reaction to the force for pushing the segments out into the formation is distributed over a substantial length of the casing, said expandable means being slips carried by the housing for limited longitudinal movement relative thereto, and an expanding wedge carried by the housing and arranged to engage and expand the slips upon relative movement occurring between the slips and housing, said slips and wedge being arranged so that when expanded one slip has its casing gripping face flush with the backside of the housing and the other side has its casing gripping face extending laterally beyond the front of the housing whereby the backside of the housing is placed in abutment with the casing along the substantial length thereof,

13. An apparatus for forcing a plurality of pipe segments from a borehole of a well laterally into a formation so as to form a flowway between the formation and the borehole comprising an elongated housing adapted to be lowered into the well, means for supporting a. pipe segment in position so that it can be pushed laterally of the housing into the formation, means in the housing for holding a supply of said segments and for feeding them one-by-one into said supporting means as a preceding segment is pushed therefrom, force transmitting means for pushing said segments without rotation from said supporting means out into the formation including a part mounted for reciprocation in the housing in the direction the segments are to be pushed and positioned to engage the rear end of a segment in the supporting means to apply a pushing force to such segment, a power cylinder having a power piston disposed therein, a force transmitting connection between the power piston and the force transmitting means moving the force transmitting means toward the segment to be pushed upon movement of the power piston in one direction, means for moving the force transmitting means away from the segment after the latter has been pushed from the housing, a power generating cylinder having a power generating piston therein, conduit means connecting the power and power generating cylinders so that hydraulic fluid can be forced from the power generating cylinder into the power cylinder to move the power piston to push a segment into a formation, said power generating piston being smaller than said power piston and having a longer stroke and said power generating piston also being disposed for reciprocation longitudinally of the housing whereby it can have a stroke much longer than the diameter of the housing to develop the requisite force for pushing the segment into a formation.

14. The apparatus of claim 13 wherein the power piston is also disposed for reciprocation longitudinally of the housing and the force transmitting connection includes a mechanical advantage linkage increasing the force transmitted from the power piston to the force transmitting means.

15. The apparatus of claim 14 wherein the mechanical advantage linkage includes a wedge connected to the power piston for reciprocation longitudinally of the housing and said force transmitting means is an anvil having a. sliding engagement with the inclined face of the wedge.

References Cited by the Examiner JACOB L. NACKENOFF, Primary Examiner.

BENJAMIN HERSH, CHARLES E, OCONNELL,

Examiners. I. A. LEPPINK, Assistant Examiner. 

1. AN APPARATUS FOR FORCING A PLURALITY OF PIPE SEGMENTS FROM A BOREHOLE OF A WELL LATERALLY INTO A FORMATION SO AS TO FORM A FLOWWAY BETWEEN THE FORMATION AND THE BOREHOLE COMPRISING AN ELONGATED HOUSING ADAPTED TO BE LOWERED INTO THE BOREHOLE, MEANS FOR SUPPORTING A PIPE SEGMENT IN POSITION SO THAT IT CAN BE PUSHED LATERALLY OF THE HOUSING INTO THE FORMATION, MEANS IN THE HOUSING FOR HOLDING A SUPPLY OF SAID SEGMENTS AND FOR FEEDING THEM ONE-BY-ONE INTO SAID SUPPORTING MEANS AS A PRECEDING SEGMENT IS PUSHED THEREFROM, FORCE TRANSMITTING MEANS FOR PUSHING SAID SEGMENTS WITHOUT ROTATION FROM SAID SUPPORTING MEANS OUT INTO THE FORMATION INCLUDING A PART MOUNTED FOR RECIPROCATION TRANSVERSELY OF THE HOUSING IN THE DIRECTION THE SEGMENTS ARE TO BE PUSHED AND POSITIONED TO ENGAGE THE REAR END OF A SEGMENT IN THE SUPPORTING MEANS TO APPLY A PUSHING FORCE TO SUCH SEGMENT, FORCE GENERATING MEANS IN SAID HOUSING INCLUDING MEANS MOVABLE LONGITUDINALLY OF THE HOUSING TO GENERATE A LONGITUDINAL FORCE WITH RESPECT TO SAID HOUSING, FORCE MULTIPLYING MEANS CONNECTING SAID LONGITUDINALLY MOVABLE MEANS AND SAID FORCE TRANSMITTING MEANS AND CONVERTING AND MULTIPLYING SAID LONGITUDINAL FORCE INTO A GREATER TRANSVERSE FORCE 